/**
 * 生成uuid
 * https://stackoverflow.com/questions/105034/create-guid-uuid-in-javascript/8809472#8809472
 */
export default function () {
  let d = Date.now()
  if (typeof performance !== 'undefined' && typeof performance.now === 'function') {
    d += performance.now() // use high-precision timer if available
  }
  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function (c) {
    var r = (d + Math.random() * 16) % 16 | 0
    d = Math.floor(d / 16)
    return (c === 'x' ? r : (r & 0x3 | 0x8)).toString(16)
  })
}
